I can't believe there has not been much talk here about the new ExoPC coming in September. Since it runs Windows 7 it should be an excellent ebook reader, not to mention all of the other things you can do with it. The specs look fantastic to me and I am purchasing one as soon as they are available. If it does have a down side it is the battery life, listed as 5 hours. Check it out here:
http://www.exopc.com/en/exopc-slate.php